/*
 * Created on Jun 11, 2009
 * Created by Paul Gardner
 * 
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License only.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

package com.aelitis.azureus.core.util;

import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.List;

import org.gudy.azureus2.core3.util.Debug;

public class DNSUtils {
    private static DNSUtilsIntf impl;

    static {
        String cla = System.getProperty("az.factory.dnsutils.impl", "com.aelitis.azureus.core.util.dns.DNSUtilsImpl");

        try {
            impl = (DNSUtilsIntf) Class.forName(cla).newInstance();

        } catch (Throwable e) {

            Debug.out("Failed to instantiate impl: " + cla, e);
        }
    }

    public static DNSUtilsIntf getSingleton() {
        return (impl);
    }

    public interface DNSUtilsIntf {
        public DNSDirContext getInitialDirContext()

        throws Exception;

        public DNSDirContext getDirContextForServer(String dns_server_ip)

        throws Exception;

        public Inet6Address getIPV6ByName(String host)

        throws UnknownHostException;

        public List<InetAddress> getAllByName(String host)

        throws UnknownHostException;

        public List<InetAddress> getAllByName(DNSUtils.DNSDirContext context, String host)

        throws UnknownHostException;

        public List<String> getTXTRecords(String query);

        public String getTXTRecord(String query)

        throws UnknownHostException;
    }

    public interface DNSDirContext {
        public String getString();
    }
}
